Sheet metal nut and process of making same



Jan. 7, 1936. E. c. BAYNES SHEET METAL NUT AND PROCESS OF MAKING SAME Filed May 13,. 1933 U ll Patented Jan. 7, I936 UNITED STATES PATENT OFFICE" SHEET METAL NUT AND PROCESS OF 2 Claims.

The present invention relates to sheet metal nuts and a process of making same.

Among the objects of the invention is to greatly reduce thecost of such articles by decreasing the amount of stock required for each.

Another object is the reduction of the cost of production in substitution of less expensive oper ations for certain-of the usual steps.

Heretofore, sheet metal nuts have been produced but by a drawing process requiring a blank sufiiciently large to provide a wide flange of metal around the draw. This is required to prevent uneven drawing, puckering, etc. and such nuts usu-- ally have the threaded wall somewhat thinner than the stock of the blank. I

In the present process a strip blank is used and the strip need be only slightly wider than the cylindrical portion of the nut. Such a saving in metal results in almost doubling the number of nuts obtainable from a given amount of metal.

The process of producing the nut and the nut itself is illustrated in the following description and the accompanying drawing in which Figure 1 is a perspective view of a suitable blank;

Figures 2 and 3 are similar views of the blank after carrying out successive steps of the process.

Figure 4 is a side view, of a finished nut.

Figure 5 is a plan view of a finished nut, and

Figure 6 is a section on line 66 of Figure 5.

As indicated in the drawing, the nut is produced from a sheet metal blank preferably rectangular in form and produced by cutting a suitable length from a strip. Such a blank is indicated on the drawing in Figure 1 and designated by the numeral E0.

The dimensions of the blank I 0 are such that its width is only slightly greater than the outside diameter of the threaded portion of the finished nut. Its length may be and preferably is suflicient to provide a fairly large area of undisturbed metal on two sides of the threaded portion.

In forming a nut from such a blank Ill, it is first punched in such fashion as to produce a short drawn flange ll around the hole and the blank then resembles the form shown in Figure 2. The punched blank of Figure 2 is then by means of suitable dies treated so as to force the flat end portions toward the flanged opening, a mandrel being used to prevent the closing of this opening. The result of-this operation is to'increase the height of the flange H while maintaining its wall thickness. The blank then resembles the form shown in Figure 3, the heightened flange being peripherally continuous and being indicated at Ila.

The blank is then ready to be threaded, and this operation is preferably accomplished by inserting into the opening a threaded mandrel which may be tapered if desired, and pressing the metal into such threads by means of a two or more part female die preferably also threaded and correlated with the mandrel so that the two sets of threads register.

As the die parts move inwardly toward the mandrel the metal of flange I la is forced into the threads thereon and some of the metal flows circumferentially and outwardly between the die parts to produce external longitudinal ribs I2. The mandrel is then removed.

If desired, the flat portions l3 of the nut may be perforated as at M at any suitable part of the process, such perforations permitting the passage of tacks to fix the nut in position on, for example, a wooden part.

Further, while the ribs l2 are desirable to prevent rotation of the nut when used in a slightly smaller bored hole, it is obvious that they may be omitted if desired. Likewise, while a rectangular blank has been shown, it, is obvious that other shapes may be used.

Now having described the invention and the preferred embodiment thereof, it is to be understood that the said invention is to be limited, not to the specific details herein set forth, but only by the scope of the claims which follow:

What I claim is:-

1. The process of producing sheet metal nuts comprising draw punching a relatively long sheet metal blank having its width only slightly greater than the outside diameter of the threaded portion of the finished nut, said draw punching operation 4 forming a flanged opening, forcing additional metal toward and into of the blank, thereby lengthening said flange, and internally threading said flange.

2. A sheet metal nut comprising an internally threaded peripherally continuous sleeve portion and a flat base portion of a width substantially the same as the outside diameter of the sleeve portion, and having the wall thickness of the sleeve portion substantially equal to that of the base portion.-

EDWARD C. BAYNES.

said flange longitudinally 

